Cardiac arrhythmias often occur as complications to cardiac diseases such as myocardial infarction and heart failure. In serious cases, arrhythmias can cause sudden death.
Atrial flutter and atrial fibrillation are the most commonly sustained cardiac arrhythmias in clinical practice. In this patent we refer to atrial fibrillation as either “atrial fibrillation” or “AF.” Currently, the development or exacerbation of AF often prompts emergency department (ED) presentations. The incidence of arrhythmias increases with age, and with the aging population in developed countries, the prevalence is expected to rise substantially over the next several decades. Overall, there are a variety of management strategies for acute atrial fibrillation and the outcomes are generally good; however, catastrophic events can occur as a result of atrial fibrillation such as congestive heart failure, thrombo-embolic phenomenon (particularly strokes), and serious adverse effects associated with treatment.
Treatment of arrhythmias such as atrial fibrillation is complex and aspects of care, especially the decision to control the ventricular rate vs. convert the arrhythmia, remain controversial. Conversion of atrial fibrillation to sinus rhythm is often attempted in the acute setting to improve symptoms and to prevent the detrimental hemodynamic effects that atrial fibrillation may have in some patients (e.g., valvular disease or left ventricular dysfunction). Early conversion of atrial fibrillation may also prevent the development of electrical remodeling and the embolic risks associated with intra-atrial thrombus formation. Electrical cardioversion is effective in restoring sinus rhythm but requires procedural sedation or anesthesia and is not successful in all cases.
Currently available converting agents have highly variable efficacy and several safety limitations associated with their use. In addition, placebo-controlled trials that establish the efficacy and safety of these pharmacological therapies for acute conversion are limited.
An efficacious, simple, and safe pharmacological alternative to existing methods of cardioversion would be a welcome development for patients with arrhythmias and their treating physicians.